Additive Value of F18-FGD-PET/CT in Pancreatic Mass Evaluation. Fathy, H1. Nasr, I2. Ali, I 3 and Tabashy, R4. 1 Nuclear Medicine Unit, National Cancer Institute, Cairo University. 2 Oncology and Nuclear Medicine Department, Faculty of Medicine, Zagazig University. 3 Radiology Department, Faculty of Medicine, Zagazig University. 4 Radiology department, National cancer Institute, Cairo University, Egypt.

Background: Accurate diagnosis and staging of pancreatic cancer are essential for appropriate treatment. The ideal imaging test for pancreatic malignancy should both detect and stage pancreatic tumor. Currently, contrast-enhanced CT with three dimensional (3-D) reconstruction is the imaging modality used for the diagnosis and staging of pancreatic cancer. FDG PET–CT may provide additional diagnostic information and improve detection rates for suspicious pancreatic lesions. The aim of the study is to evaluate the diagnostic impact of FDG-PET/CT in patients with solid pancreatic masses, compared to the contrast enhanced CT (CECT) and Endoscopic Retrograde Cholangio-Pancreatography (ERCP).Material and Methods: Twenty seven patients with solid pancreatic masses underwent CECT of the neck, chest and pelvi-abdominal, ERCP and FDG-PET/CT examinations from January 2014 to May 2015.
Both imaging methods were done within one month interval. PET–CT data sets were analyzed by two expert readers in a consensus reading. Biopsy from ERCP, surgery/fine needle aspiration with histological examination was also done for all patients. Results: Twenty four patients of the total 27 patients (88.9%) had pancreatic cancer and 3 patients (11.1%) had benign lesions. PET/CT detected head masses in (17/27) patients (63%) versus (12/27) for CECT (44.8%) and (9/27) for ERCP (33.3%).PET/CT had greater sensitivity than CECT (79.2% versus 62.5%) in diagnosis of pancreatic lesions. Corresponding specificities were similar between both imaging methods.
Accuracy was 74.1% for PET/CT Vs 59.3% for CECT. PET/CT had higher degree of accuracy for detection of distant metastases in LNs and liver compared with that of CECT. Three patients with vascular infiltration were diagnosed only with CECT. PET/CT upstaged 8 patients from stage IA, IB and IIB to stage III and stage IV.
Conclusion: PET/CT is valuable additional imaging method in characterization and staging patients with suspected malignant pancreatic masses. Incorporation of PET/CT improves the preoperative evaluation of patients with solid pancreatic lesions especially in detection of additional metastatic sites.